The present invention relates to systems for delivering oxygen to patients undergoing respiratory therapy, and particularly to oxygen-delivery systems including an oxygen meter. More particularly, the present invention relates to a portable oxygen meter for use with an oxygen-delivery system.
Supplemental oxygen-delivery systems are provided to administer medicinal gas, normally oxygen, to a patient undergoing respiratory therapy. Supplemental oxygen-delivery systems are used by patients that benefit from receiving and breathing oxygen from an oxygen supply source to supplement atmospheric oxygen breathed by the patients. A compact, portable supplemental oxygen-delivery system is useful in a wide variety of contexts, including hospital, home care, and ambulatory settings.
High-pressure supplemental oxygen-delivery systems typically include a cylinder or tank containing oxygen gas at a pressure of up to 3000 psig. A pressure regulator is used in a high-pressure oxygen-delivery system to xe2x80x9cstep downxe2x80x9d the pressure of oxygen gas in the tank to a lower pressure level (e.g., 20 or 50 psig) suitable for use in an oxygen-delivery apparatus used by a patient in respiratory therapy.
According to the present invention, an oxygen-delivery system includes a low-pressure oxygen supply, a portable oxygen meter including a pneumatic demand oxygen conserver, a flexible supply tube to conduct low-pressure oxygen from the low-pressure oxygen supply to the portable oxygen meter, and a nasal cannula coupled to the portable oxygen meter and adapted to be inserted into the nasal cavities of a patent. The portable oxygen meter operates to meter low-pressure oxygen flowing therethrough so that the low-pressure oxygen is discharged from the portable oxygen meter to a patient through the nasal cannula at a selected oxygen flow rate.
In preferred embodiments, the portable oxygen meter includes a manifold formed to include a low-pressure oxygen inlet coupled to an outlet end of the flexible supply tube to receive low-pressure oxygen flowing through the tube, and a flow controller module mounted on one side of the manifold. The pneumatic demand oxygen conserver is contained in a module mounted on an opposite side of the manifold and coupled to the nasal cannula.
Low-pressure oxygen is discharged from the flexible supply tube into the manifold and the oxygen is passed through one of several oxygen flow-metering apertures (of varying sizes) located in the flow controller module to regulate and set the flow rate of low-pressure oxygen (measured in liters per minute) that is conducted from the flow controller module (back through the manifold) to the pneumatic demand oxygen conserver for distribution to a patient via the nasal cannula. The pneumatic demand oxygen conserver functions to take metered, low-pressure oxygen from the flow-controller module and distribute it to a patient at various times in response to inhalation of the patient through the nasal cannula.
Low-pressure oxygen is discharged into the inlet end of the flexible supply tube from a low-pressure supply of liquid oxygen or from a tank containing high-pressure oxygen and a pressure regulator configured to xe2x80x9cstep downxe2x80x9d the pressure of oxygen in the tank to a lower pressure level. The length of the flexible supply tube can be fairly long (e.g., over twenty feet) to enhance the portability of the portable oxygen meter.
A meter mount is coupled to the manifold and adapted to be worn by a patient to minimize the length of the nasal cannula that carries metered, low-pressure oxygen from the portable oxygen meter to the patient. The meter mount includes lugs that fit into notches formed in the manifold and a clip adapted to be coupled to a belt worn by the patient. Other meter mounts are also disclosed herein.
Additional features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.